Tubulars for a well bore are assembled at the surface as single joints are added and the tubular string is lowered into the well bore. As the joints are added at the surface on the rig floor, it is sometimes desirable to fill the tubular. Filling the tubular before it is run into the well bore prevents pressure imbalances on the tubular as it is being advanced into the well bore. Additionally, once the tubular is filled, it may be desirable to circulate through the tubular string as it is advanced into the well bore.
Casing is often run into the well bore as a liner. Liners of the desired length are advanced into the well bore as a casing string then attached to a hanger. The liner is further advanced into the well bore using the tubular string normally used to drill the well. Liners are advanced to a point near the bottom of the previously run casing string and cemented in the newly drilled portion of the well bore.
In addition to the cases cited above, the casing or drill string being advanced into the well bore may fit so tightly into the casing previously cemented in the well or the open hole below the previously run casing string that a pressure surge would be generated below the casing shoe or bottom hole assembly of a drill string. This is very undesirable since this pressure surge could break down an open formation causing loss of drilling fluid and/or loss of control of the well. To reduce the surge pressure it may be desirable to use a float shoe or valving in a drill string that allows well fluid to enter the casing and/or the drill string as they are being advanced into the well bore. To handle the fluid entering the casing, the fluid must be captured at the surface as it flows from the tubular string and returned to the mud system otherwise the fluid would spill on the rig floor and into the environment.
Prior devices have been developed to fill the casing and to circulate it and devices have been developed to fill the drill string and circulate it. These apparatus are illustrated in U.S. Pat. Nos. 4,997,042; 5,191,939; 5,735,348; 5,971,079 and 6,173,777 are apparatus to fill and circulate the casing; apparatus illustrated in U.S. Pat. Nos. 6,390,190; 6,415,862; 6,578,632 and 6,604,578 are to fill and circulate the drill string.
Currently, one of the above mentioned apparatus would be rigged up then used for advancing the casing into the well bore then removed from the rig. Another apparatus would then be rigged up to provide a means for advancing the drill string into the well bore. Currently none of the apparatus illustrated in the forgoing patents are able to fill, circulate and take returns from both the casing and drill string. In addition to the circulating apparatus change from casing to drill pipe the handling systems used on the top drive or traveling block must also be changed. That is to say casing elevators are removed and replaced by drill pipe elevators. This change over require substantial time when it is most critical to keep the tubular string moving (part of the tubular is in the open hole).
Some of these apparatus are attached to and held in place by a top drive or traveling block at the upper end and seal on or in the tubular at the lower end of the apparatus. When pressure is applied to the tubular through these apparatus a force is applied upward on the apparatus and downward on the tubular. This force will add to the load carried by the bails and elevators used to support the tubular and may cause an overload condition on these pieces of equipment.
Accordingly, it is an object of the present invention to provide an apparatus and means for filling and circulating any combination of tubular advanced into are removed from the well bore utilizing the same fill or circulation apparatus while changing the thread protector having a special internal profile.
Accordingly, it is an objective of the present invention to replace the bails and elevators used to handle the tubular while advancing/removing it in/from the well bore.
Accordingly, it is an objective of the present invention to eliminate the loading of the load carrying equipment (elevators, bails, traveling block or top drive).